Sound absorbing porous concretes composed of different solid wastes

This study had a triple environmental objective. First, to reuse various industrial wastes (i.e., bottom ash, slag, and construction and demolition waste) as coarse aggregates in porous concretes. Second, to develop a material capable of eliminating noise, another environmental pollutant, in acoustic barriers. The third objective was to produce construction materials composed primarily of wastes with no impact on the environment or human health (regarding the leaching of heavy metals). We conducted several tests of recycled porous concretes to determine if they can be used as raw material to produce highway noise barriers. The tests dealt with physical (open void ratio, bulk density) mechanical (compressive strength), acoustic (sound absorption coefficient) and leaching properties. We analyzed the influence of particle size. We found that the source of the waste does not affect the sound absorption properties if the particle size is similar. However, the source of the waste slightly influences the mechanical properties and substantially affects the leaching of the final product. Hence, different wastes can be compounded to manufacture porous concrete if they do not pose problems of heavy metal leaching.